1. Field of the Invention
The present invention relates to a jigsaw puzzle comprising a plurality of interlocking puzzle pieces to complete a design on the surface of the puzzle pieces as a pastime that has long been enjoyed by players, and in particular, relates to a jigsaw puzzle which enables the seeing of the design in the dark by emitted light from a luminous material.
2. Related Art
Conventionally, a jigsaw puzzle having a design which was visible in the dark was nearly produced by applying a luminous pigment or the like to draw a simple picture like a chart on a pattern which was printed on the surface of a jigsaw puzzle. In the conventional method, a fine line of the luminous pigment or the like is applied along the outlines of the design or along the outlines of other configurations to emit light from the applied lines in the dark.
However, in the conventional method, the work of application of the luminous pigment or the like to draw a picture like a chart was relatively troublesome. The luminous pigment or the like of the conventional jigsaw puzzle had a limited ability to store light, so that the light-emitting time according to the luminous pigment or the like was very short such as several tens of seconds. Furthermore, since light was emitted from only the applied portion of the luminous pigment or the like, it was difficult to see the design on the surface of the jigsaw puzzle.